1. Field of the Invention
The present invention relates to a muting device built in an upright piano, which, reduces a tone volume of a piano sound.
2. Prior Art
In the conventional muting device of the upright piano, by stepping on a soft pedal, a hammer interlocking with the soft pedal is moved close to a string to thereby reduce a string-striking distance between them. This kind of muting device provides a transmitting mechanism which transmits a motion of a key to the hammer. However, among parts of the transmitting mechanism, there must be a gap between a jack and a butt, which deteriorates a key-touch feeling.
In order to eliminate such drawback, several types of muting devices, as disclosed in Japanese Utility-Model Laid-Open Publication No. 52-9429, Japanese Patent Laid-Open Publication No. 61-52696 and Japanese Utility-Model Laid-Open Publication No. 62-71690, are proposed, in which the wippen or the back side of key are raised in connection with the motion of the soft pedal.
However, even in the above-mentioned, improved muting device, there must be some problems as described below.
In the muting device employing the structure in which the wippen is raised, the key-striking operation is identical to that of the conventional muting device. Therefore, rotation range of the wippen must become too large, which reduces a hammer-stopping stroke. In addition, a distance between the jack and regulating button must be shortened, so that an escape timing of the jack must become too earlier, which deteriorates the key-touch feeling.
On the other hand, in the muting device employing the structure in which the back side of key is raised, the above-mentioned problems are not present. However, the key stroke must be reduced, by which the performer cannot obtain the satisfactory key-touch feeling.